Mature Incisor With Internal Resorption: Laser-Assisted Regenerative Endodontic Procedures

Internal root resorption (IRR), characterized by progressive dentin destruction, may cause root perforations, fracture, and even tooth loss. Regenerative endodontic procedures (REPs), which can promote root development, lack strong evidence for treating IRR. This report demonstrates a successful treatment of trauma-induced IRR in a mature incisor by laser-assisted REPs. A 24-year-old female with trauma history applied for tooth restoration. Clinical examination showed a filling on tooth #21 with normal mobility, healthy gingiva and negative response to probing/percussion/vitality tests. CBCT demonstrated complete apical closure with thin canal wall, and apical-third IRR communicating with distal periodontal lesion. Er:YAG laser disinfection and calcium hydroxide medication were performed following access cavity preparation under rubber-dam isolation. REPs were performed after 3-month infection management. A #40 K-file was inserted through the IRR-induced lateral perforations to provoke bleeding from periodontal tissues, followed by iRoot BP placement over the blood clot. A 3-year follow-up revealed periapical healing, arrested resorption, thickened canal wall, and perforation repair. The dual disinfection combining laser irradiation and chemical medication created an aseptic environment critical for subsequent strategic bleeding induction through IRR-induced lateral perforations, transforming pathological perforations into gateways for intracanal vascularization, which facilitated hard tissue regeneration of canal wall and alveolar bone. This case validates the efficacy of laser-assisted REPs in managing IRR of mature permanent teeth, where limited apical blood-supply was compensated by periodontal blood influx through IRR-induced lateral perforations, thereby enhancing REPs outcomes.